A warehouse is a facility primarily used for storage of goods for commercial purposes. The storage is generally intended to be temporary; as such goods ultimately may be intended for a retailer, consumer or customer, distributor, transporter or other subsequent receiver. A warehouse can be a standalone facility, or can be part of a multi-use facility. Thousands of types of items can be stored in a typical warehouse. The items can be small or large, individual or bulk. It is common to load items on a pallet for transportation, and the warehouse may use pallets as a manner of internally transporting and storing items.
A well-run warehouse is well-organized and maintains an accurate inventory of goods. Goods can come and go frequently, throughout the day, in a warehouse. In fact, some large and very busy warehouses work three shifts, continually moving goods throughout the warehouse as they are received or needed to fulfill orders. Shipping and receiving areas, which may be the same area, are the location(s) in the warehouse where large trucks pick-up and drop-off goods. The warehouse can also include a staging area—as an intermediate area between shipping and receiving—and storage aisles and areas within the warehouse where the goods are stored. The staging area, for example, can be used for confirming that all items on the shipping manifest were received in acceptable condition. It can also be used to assemble or otherwise prepare orders for shipping.
Goods in a warehouse tend to be moved in one of two ways, either by pallet or by cart (or trailer). A pallet requires a pallet transport for movement, such as a pallet jack, pallet truck, forklift, or stacker. A stacker is a piece of equipment that is similar to a fork lift, but can raise the pallet to significantly greater heights, e.g., for loading a pallet on a warehouse shelf A cart requires a tugger (or “tow cart”), which pulls the cart from place to place.
A pallet transport can be manual or motorized. A traditional pallet jack is a manually operated piece of equipment, as is a traditional stacker. When a pallet transport is motorized, it can take the form of a powered pallet jack, pallet truck, or forklift (or lift truck). A motorized stacker is referred to as a power stacker. A motorized pallet jack is referred to as a powered pallet jack, which an operator cannot ride, but walks beside. A pallet truck is similar to a powered pallet jack, but includes a place for an operator to stand.
As with motorized pallet transports, a tugger can be in the form of a drivable vehicle or in the form of a powered vehicle along the side of which the operator walks. In either form, a tugger includes a hitch that engages with a companion part on the cart, such as a sturdy and rigid ring or loop.
Automatic guided vehicle (AGV) forms of pallet trucks and powered tuggers exist. An AGV is a mobile robot that follows markers or wires in the floor, or uses vision or lasers to make its way without direct or remote control by an operator. They are most often used in industrial applications to move materials around a manufacturing facility or a warehouse, such as in the case of AGV forklifts and AGV tuggers.
To date, pallet transports and tuggers represent two distinct types of equipment. In the case of powered equipment, such units are not only expensive to purchase or lease, but can also be expensive to maintain. For this reason, motorized pallet transports and tuggers tend to be in short supply in a warehouse, and if such a unit becomes inoperable, the efficiency of the warehouse is naturally negatively impacted. Such negative impacts can ripple though the supply chain, as an underperforming warehouse can cause delays in receiving and shipping of goods.
FIG. 1 is a perspective view of a pallet truck 100, as an example. The pallet truck 100 includes a rear load portion 110, where a pair of forks 112 is located to engage and lift a pallet. The forks 112 can be raised and lowered. As is known in the art, the forks 112 are lowered to engage the pallet, and then raised to lift the pallet from the floor. Once the pallet is raised, the pallet truck 100 can transport the pallet to another location, using load wheels 114 located in distal ends of the forks 112. Wheels 114 share a common axis, represented by centerline C.
The pallet truck 100 includes a front drive portion 120 that includes a housing 122, within which may be located a motor and drive mechanism (not shown). Within or adjacent to housing 122 is a battery 123. Pallet truck 100 is controlled using a drive control arm 124, which includes start, drive, and stop mechanisms. A wheel (not shown) is also located in the front drive portion 120, usually beneath a linkage (not shown) at the bottom of drive control arm 124.